From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:33543 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1425860AbdD1WAI (ORCPT ); Fri, 28 Apr 2017 18:00:08 -0400 Date: Sat, 29 Apr 2017 00:00:05 +0200 From: Pavel Machek To: Mauro Carvalho Chehab Cc: Sakari Ailus , Sakari Ailus , linux-media@vger.kernel.org Subject: Re: [PATCH v3 1/2] v4l: Add camera voice coil lens control class, current control Message-ID: <20170428220004.GA23906@amd> References: <1487074823-28274-1-git-send-email-sakari.ailus@linux.intel.com> <1487074823-28274-2-git-send-email-sakari.ailus@linux.intel.com> <20170414232332.63850d7b@vento.lan> <20170416091209.GB7456@valkosipuli.retiisi.org.uk> <20170419105118.72b8e284@vento.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="a8Wt8u1KmwUX3Y2C" Content-Disposition: inline In-Reply-To: <20170419105118.72b8e284@vento.lan> Sender: linux-media-owner@vger.kernel.org List-ID: --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Hmm... if the idea is to have a control that doesn't do ringing > compensation, then it should be clear at the control's descriptions > that: >=20 > - V4L2_CID_FOCUS_ABSOLUTE should be used if the VCM has ringing > compensation; > - V4L2_CID_VOICE_COIL_CURRENT and V4L2_CID_VOICE_COIL_RING_COMPENSATION > should be used otherwise. >=20 > Btw, if the rationale for this patch is to support devices without > ring compensation, so, both controls and their descriptions should > be added at the same time, together with a patchset that would be > using both. >=20 > > How about adding such an explanation added to the commit message? >=20 > It is not enough. Documentation should be clear that VCM devices > with ring compensation should use V4L2_CID_FOCUS_ABSOLUTE. Is ring compensation actually a big deal? We do not publish enough information to userland about how fast the autofocus system is, anyway, so it looks like userland can't depend on such details... Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --a8Wt8u1KmwUX3Y2C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlkDu2QACgkQMOfwapXb+vLqYgCeNpXlRMeTg+9UQtMPv6mHHrH6 pO0An1dDK5AoJDtBf5ZC6RckgiQt8cto =o4H3 -----END PGP SIGNATURE----- --a8Wt8u1KmwUX3Y2C--